A dairy farmer near Willunga says he's been raided by Biosecurity SA and the police for selling raw or unpasteurised milk.

It's illegal to sell raw milk in South Australia, so some consumers who want the product buy shares in a cow, then collect the milk it produces to avoid having to buy the milk itself.

Mark Tyler, a dairy farmer from Willunga says he was shocked to see the people turn up unannounced, and says that many of the health concerns about providing consumers with unprocessed milk are no longer applicable as vaccines and the eradication of some diseases has lowered the risks.

David Basham, president of the South Australian Dairyfarmers Association says that as an industry they don't want to see raw milk sold as they see the health risks as too great.

Geoff Raven from Biosecurity SA says that they have asked the dairy farmer involved to become an accredited farmer, who would then not be allowed to offer untreated milk to consumers.